Derogatory term used to describe one's crappy local community college. The community college is seen as both lacking in real collegiate educational value and additionally using no discretion in its acceptance of every single applicant. It is described as the 13th grade to imply that it is merely an extension of public high school. It is considered only one step above going to beauty school or training in air conditioning and refrigeration repair.

"Judy didn't get accepted by Trenton State, so she's going to the 13th grade"

Any community college, especially Harrisburg Area Community College (HACC). It's basically the same exact thing as high school, except it's easier and people around you are generally not the sharpest tools in the shed and give even less of a shit than they did before. See also the bomb diggity.

Looks like Joe has to repeat 13th grade. I guess he just couldn't HACC it.

a term used to describe the first year of school at the local community college. The term plays on the fact that students are going to school in the same town as their high school with many of the same students from their high school class.

She was supposed to leave for college in August, but then she got pregnant. I guess she'll go to 13th grade instead.